U.S. patent application number 12/564281 was filed with the patent office on 2010-06-24 for temperature control system for an on board inert gas generation systems.
Invention is credited to Eric Surawski.
Application Number | 20100155046 12/564281 |
Document ID | / |
Family ID | 41694614 |
Filed Date | 2010-06-24 |
United States Patent
Application |
20100155046 |
Kind Code |
A1 |
Surawski; Eric |
June 24, 2010 |
TEMPERATURE CONTROL SYSTEM FOR AN ON BOARD INERT GAS GENERATION
SYSTEMS
Abstract
An apparatus for providing air at a given temperature to an air
separation module has a first path for delivering air having a
temperature to the air separation module, a second path for
delivering air having a temperature to the air separation module, a
heat exchanger through which the second path flows, the heat
exchanger modulating the temperature of the air from the given
temperature to a second temperature, and a valve for controlling an
amount of air flowing through the second path whereby if the air
delivered to the air separation module by the first path and the
second path is below a temperature desired to run the air
separation module essentially all of the air may flow through the
first path.
Inventors: |
Surawski; Eric;
(Wethersfield, CT) |
Correspondence
Address: |
CARLSON, GASKEY & OLDS, P.C.
400 WEST MAPLE ROAD, SUITE 350
BIRMINGHAM
MI
48009
US
|
Family ID: |
41694614 |
Appl. No.: |
12/564281 |
Filed: |
September 22, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61203081 |
Dec 18, 2008 |
|
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Current U.S.
Class: |
165/287 |
Current CPC
Class: |
B64D 37/32 20130101 |
Class at
Publication: |
165/287 |
International
Class: |
G05D 23/00 20060101
G05D023/00 |
Claims
1. An apparatus for providing air at a given temperature to an air
separation module comprising: a first path for delivering air
having a temperature to said air separation module, a second path
for delivering air having a temperature to said air separation
module, a heat exchanger through which said second path flows, said
heat exchanger modulating said temperature of said air from said
given temperature to a second temperature, and a valve for
controlling an amount of air flowing through said second path
whereby if said air delivered to said air separation module by said
first path and said second path is below a temperature desired to
run said air separation module essentially all of said air may flow
through said first path.
2. The apparatus of claim 1 wherein said first path and said second
path join downstream of said heat exchanger.
3. The apparatus of claim 1 further comprising: a compressed air
source for providing compressed air having a temperature to said
first and second paths.
4. The apparatus of claim 1 wherein said valve is located upstream
of said heat exchanger
5. The apparatus of claim 1 wherein said valve is located
downstream of said heat exchanger.
6. A method for providing air at a given temperature to an air
separation module that operates at or within a desired temperature
range and encounters cooler temperatures comprising: providing a
first flow of air to an air separation module, selectively
providing a second flow of air to a heat exchanger, mixing said
first flow of air with said second flow of air if said mixing
delivers said air at or within said desired temperature range.
7. The method of claim 6 further comprising: delivering said mixed
flow of air to said air separation module.
8. The method of claim 6 further comprising: not mixing said first
flow of air with said second flow of air if said mixing does not
deliver said air at or within said desired temperature range.
9. The method of claim 6 wherein said selectively providing said
second flow comprises valving provided upstream of said heat
exchanger.
10. The method of claim 6 wherein said selectively providing said
second flow comprises valving provided downstream of said heat
exchanger.
Description
RELATED APPLICATION
[0001] This application claims priority to U.S. Provisional Patent
Application 61/203,081, which was filed Dec. 18, 2008.
BACKGROUND
[0002] Aircraft may use on board inert gas generating system
("OBIGGS") to minimize fuel tank accidents. Potentially dangerous
fuel and air mixtures (such mixtures known as "ullage") in the air
space in fuel tanks are diluted and minimized by reducing the
oxygen content of ullage. The OBIGGS accomplishes this by adding
nitrogen enriched air (NEA) to the ullage. The OBIGGS separates
oxygen from ambient air and pumps relatively inert, oxygen
impoverished NEA to the fuel tanks.
[0003] The OBBIGS may produce NEA by using permeable membranes in
an air separation module ("ASM"). The ASM typically has a bundle of
hollow, permeable fiber members packaged in a cylindrical shell
with an inlet, an outlet at the ends of the shell and a side vent
port. Pressurized air enters the ASM inlet and, as it passes
through the hollow fibers, oxygen is separated from the air stream
due to diffusion through the fiber walls. Oxygen exits through the
side vent port and can be captured, but often the oxygen is
considered a waste gas and is exhausted overboard.
[0004] The remaining air is deemed to be nitrogen enriched because,
due to normal levels of gas in the air, if all the oxygen is
removed from air, about 97% of the remaining air is nitrogen.
Normal concentrations of oxygen in the NEA are usually above
zero.
[0005] The remaining NEA flows out of the ASM via the outlet port
and is distributed to the ullage space of the fuel tank or tanks
for the purpose of inerting the fuel tanks and reducing a
possibility of flammability. The ASM operates most efficiently, in
terms of permeability of oxygen through the tubes at an elevated
temperature, usually between 180.degree. and 200.degree. F.
[0006] Pressurized air used for NEA generation will usually
originate from either an engine bleed or from another pressure
source within the aircraft. With an engine bleed system, compressed
hot air is usually cooled by a heat exchanger to an optimal
temperature before being vented to an ASM.
SUMMARY
[0007] According to a non-limiting embodiment of the invention, an
apparatus for providing air at a given temperature to an air
separation module has a first path for delivering air having a
temperature to the air separation module, a second path for
delivering air having a temperature to the air separation module, a
heat exchanger through which the second path flows, the heat
exchanger modulating the temperature of the air from the given
temperature to a second temperature, and a valve for controlling an
amount of air flowing through the second path whereby if the air
delivered to the air separation module by the first path and the
second path is below a temperature desired to run the air
separation module essentially all of the air may flow through the
first path.
[0008] According to another non-limiting embodiment shown herein, a
method for providing air at a given temperature to an air
separation module that operates at a desired temperature range and
encounters cooler temperatures includes providing a first flow of
air to an air separation module, selectively providing a second
flow of air to a heat exchanger, and mixing the first flow of air
with the second flow of air if mixing delivers the air at or within
the desired temperature range.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] These and other features of the present embodiment may be
shown and best understood from the following specification and
drawings.
[0010] FIG. 1A is a first schematic, prior art depiction of an
OBIGGS delivering air to an ASM.
[0011] FIG. 1B is a second schematic, prior art depiction of an
OBIGGS delivering air to an ASM.
[0012] FIG. 2 is a schematic view of a non-limiting embodiment of
an OBIGGS delivering air to an ASM.
[0013] FIG. 3 is a schematic view of a non-limiting embodiment of
an OBIGGS delivering air to an ASM.
DETAILED DESCRIPTION
[0014] Referring now to FIG. 1A, a prior art depiction of an OBIGGS
10 delivering compressed air to an ASM 15 is shown. A compressed
air source 20, such as an aircraft engine (not shown), delivers
compressed air to the ASM 15 through ducting 60 and two separate
paths. The first path 25 delivers a first portion of the heated,
compressed air, without any gating thereof, through a heat
exchanger 30. The heat exchanger takes the heated compressed air
and cools it with air from ambient or another cooled air source 35
within an aircraft (not shown). The second path 40 delivers a
second portion of the heated, compressed air through a valve 45 to
be mixed with air in the first path 25 downstream of the air
provided through the heat exchanger 30.
[0015] Typically, an ASM 15 requires air at or about
180-200.degree. F. to operate efficiently. Air from the compressed
air source 20 is typically supplied at temperatures ranging from
300-500.degree. F. A sensor 50 determines the temperature of the
air entering the ASM and a controller 55 receives feedback from the
sensor 50 and controls a position of the valve 45 so that a mixture
of different temperature air from the first path 25 and the second
path 40 is provided to the ASM at a proper temperature.
[0016] Referring now to FIG. 1B, a second prior art system of an
OBIGGS 65 delivering compressed air to an ASM 115 is shown.
According to this system, all air intended for the ASM 115 is sent
through a heat exchanger 130 that cools the air intended for ASM.
This system modulates the temperature of the air intended for the
ASM by controlling an amount of air provided to the heat exchanger
135 by valve 145. A sensor 150 determines the temperature of the
air entering the ASM 115 and a controller 155 receives feedback
from the sensor 150 and controls a position of the valve 145
ducting cooling air to the heat exchanger 130 so that the air
intended for the ASM 115 is cooled to the proper temperature range
to run the ASM 115 efficiently.
[0017] There are problems with the prior art systems shown in FIGS.
1A and 1B. There are large heat losses during cruise in the ducting
60, 160 and the paths 40, 140, 25, 125 between the compressed air
source 20,120 and the heat exchanger 30, 130 and the ASM 15, 115.
Temperatures at 30,000 feet, for instance may be -30.degree. F. or
lower. Such low temperatures can cause great heat losses in the
system. These heat losses can cause the maximum temperature of air
delivered to the ASM to be below the optimal temperature range to
run the ASM efficiently. Further complicating the issue of heat
loss in the ducts, aircraft engines (not shown) require less power
at altitude and engine bleed air temperature may at the lower end
of the bleed air temperature range.
[0018] For instance, in FIG. 1A, air passing through the heat
exchanger 30 is not modulated so that the very cool air at altitude
passing through the heat exchanger 30 and the cool air affecting
the ducting 60 and paths 25, 45 may combine to lower the
temperature below 180.degree. F. even if the valve 45 allowing air
at higher temperature to pass through the second path 40 is fully
open. Compressed air in the first path 25 passing through the heat
exchanger 30 may lower the temperature too much to allow the amount
of higher temperature compressed air passing through the valve 45
in the second path 40 to raise the air temperature enough to heat
the air between 180-200.degree. F.
[0019] Similarly, in FIG. 1B, the higher temperature compressed air
always passes through the heat exchanger 130. Even though cooling
air from cooling air source 135 passing through the heat exchanger
130 can be modulated, temperature losses in the ducting 160 and the
paths 125, 140 and a radiator effect of the heat exchanger 135 may
cause the temperature of the air delivered to the ASM to be below
180.degree. F. This may be true even if the valve 145 allowing
cooler air from the cooling air source 135 to pass through the heat
exchanger is fully closed.
[0020] Referring to FIG. 2, a non-limiting embodiment of an OBIGGS
70 delivering compressed air to an ASM 215 is shown. In this
embodiment, a compressed air source 220 communicates compressed air
having an elevated temperature via duct 260 and a first path 240 in
which the compressed air passes directly to the ASM 215. The
compressed air source also communicates compressed air having an
elevated temperature via a second path 225 through a heat exchanger
230. The second path 225 through the heat exchanger is modulated by
a valve 245 located downstream of the heat exchanger 230. A sensor
250 determines the temperature of the air entering the ASM 215 and
a controller 255 receives feedback from the sensor and controls a
position of the valve 245 so that a mixture of different
temperature air from the first path and the second path is provided
to the ASM at a proper temperature.
[0021] Referring still to FIG. 2, if the valve 245 controlling
cooling air flow through the heat exchanger 230 is shut, the higher
temperature compressed air travels through the first path 240 to
the ASM directly. In other words, contrary to the prior art, the
output of the higher temperature compressed air may be delivered
directly to the ASM without passing through a heat exchanger 230
first (see also FIGS. 1A and 1B) so that heat loss in the ducting
260, the second path 225 and the heat exchanger 230 does not drop
the temperature of air entering the ASM 215 below the required
temperatures. Cooling may not be necessary if heating losses in the
compressed air passing through the heat exchanger 230 and the paths
225, 240 and ducting 260 is too great.
[0022] Referring to FIG. 3, a further non-limiting embodiment of an
OBIGGS 70 delivering compressed air to an ASM 315 is shown. In this
embodiment, a compressed air source 320 communicates compressed air
having an elevated temperature via duct 360 and a first path 340 in
which the compressed air passes directly to the ASM 315. The
compressed air source also communicates compressed air having an
elevated temperature via a second path 325 through a heat exchanger
330. The ratio of air passing through the first path 340 and the
second path 325 through the heat exchanger is modulated by a valve
345 that is located upstream of the heat exchanger 330. A sensor
350 determines the temperature of the air entering the ASM 315 and
a controller 355 receives feedback from the sensor 350 and controls
a position of the valve 345 so that a mixture of different
temperature air from the first path and the second path is provided
to the ASM at a proper temperature.
[0023] Referring still to FIG. 3, if the valve 345 controlling
cooling air flow through the heat exchanger 330 is shut, the higher
temperature compressed air travels through the first path 340 to
the ASM directly. In other words, contrary to the prior art, the
output of the higher temperature compressed air may be delivered
directly to the ASM without passing through a heat exchanger 330
first (see also FIGS. 1A and 1B) so that heat loss in the ducting
360, the second path 325 and the heat exchanger 330 does not drop
the temperature of air entering the ASM 315 below the required
temperatures. Cooling may not be necessary or desirable if heating
losses in the compressed air passing through the heat exchanger 330
and the paths 325, 340 and ducting 360 is too great.
[0024] The foregoing description is exemplary rather than defined
by the limitations within. Various non-limiting embodiments are
disclosed herein, however, one of ordinary skill in the art would
recognize that various modifications and variations in light of the
above teachings will fall within the scope of the appended claims.
It is therefore to be understood that within the scope of the
appended claims, the invention may be practiced other than as
specifically described. For that reason the appended claims should
be studied to determine true scope and content.
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